c=int(input('请输入成绩：'))
if c>100 or c<0:
   print("date error!")
elif c>=90:
   print("五分制成绩为A")
elif c>=80:
   print("五分制成绩为B")
elif c>=70:
   print("五分制成绩为C")
elif c>=60:
   print("五分制成绩为D")
else:
   print("五分制成绩为E")